Temperature Characteristics Studies of Nanocrystallite SrTiO₃ Grain Boundaries by X-Ray Photoelectron Spectroscopy

Strontium titanate (SrTiO₃) nanocrystallite thin films have been studied by x-ray photoelectron spectroscopy at different temperature. The surface oxygen concentration and Ti/Sr ratio increase with temperature rising up to 700K, and then decrease. New O1s and Ti 3d peaks appear at the low binding energy side of the corresponding main peaks, these new peaks have some different features from the corresponding main peaks, this phenomenon was not observed in single crystal SrTiO₃. A model is proposed to explain this interesting phenomenon.